Mortar with electro-magnetic retaining coil

ABSTRACT

A mortar or short barrel weapon including a rifled barrel for propelling and rotating a projectile. The base plate, supports, and sighting components are conventional. This invention pertains to a newly improved design for a projectile for use in combination with a mortar barrel including an electro-magnetic retention means designed to momentarily restrain the projectile in the breech of the barrel promoting burning of the propelling charge while momentarily retaining the projectile resulting in increased pressures, muzzle velocity and range. The magnetic retention means comprises a retaining coil or coils selectively activated and deactivated by a control circuit comprising switches, coils, and conductors. An alternative mechanical retaining means is suggested utilizing retaining pins employing mechanical, hydraulic, or electro-magnetic control means.

Pelaez Dec. 18, 1973 [76] Inventor: Pedro B. Pelaez, Cedar Hill Ranch,

Vanderpool, Tex. 78885 [22] Filed: Apr. 25, 1972 [21] Appl. N0.: 245,467

[52] 11.5. C1 89/1 F, 89/1.806 [51] llnt. Cl ..F411f1/06 [58] Field ofSearch 89/1 F, 1 J, 1.806, 89/1.807; 124/3 [56] References Cited UNITEDSTATES PATENTS 2,383,053 8/1945 Fanger et a1. 89/1 F 1,589,194 6/1926Maxwell 89/1 .1 1,602,037 10/1926 Mixsell 89/1 F 397,052 1/1889Emmens..... 89/1 F 421,307 2/1890 Reyno1ds.... 89/1 F 1,257,126 2/1918Schneider... 89/1 F 2,307,009 1/1943 Adelman 89/1 F 2,353,885 7/1944Fanger et a1. 89/1 F FOREIGN PATENTS OR APPLlCATlONS 147,257 10/1936Austria 89/1 F 733,944 4/1943 Germany 89/1 F Primary Examiner--BenjaminA. Borchelt Assistant Examiner-C. T. Jordan Att0rney--Willard J. Hodges,Jr.

[5 7] ABSTRACT A mortar or short barrel weapon including a rifled barrelfor propelling and rotating a projectile. The base plate, supports, andsighting components are conventional. This invention pertains to a newlyimproved design for a projectile for use in combination with a mortarbarrel including an electro-magnetic retention means designed tomomentarily restrain the projectile in the breech of the barrelpromoting burning of the propelling charge while momentarily retainingthe projectile resulting in increased pressures, muzzle velocity andrange. The magnetic retention means comprises a retaining coil or coilsselectively activated and deactivated by a control circuit comprisingswitches, coils, and conductors. An alternative mechanical retainingmeans is suggested utilizing retaining pins employing mechanical,hydraulic, or electro-magnetic control means.

8 Claims, 9 Drawing Figures PATENTEDBECI 8 @121 3,779,128

SHEET 2 0F 3 FIG. 5

PATEINED 9W3 3,779,128

SHEEI 3 BF 3 FIG. 6 FIG] FIG. 9

FIG. 8

MORTAR wITII ELECTRO-MAGNETIC RETAINING CoII.

BACKGROUND OF THE INVENTION 1. Field of the Invention This inventionrelates primarily to an infantry weapon employed by the armies of theworld as a close support weapon. Weapons of this class vary in diameterof the projectile from approximately 60mm to 120mm. The 81mm mortar andcomparable calibers are widely used by U. S. forces and armies of theworld. The device of this invention pertains to an improvement in thiscategory of weapons which results in an increased range for the weapon.

2. Description of the Prior Art Mortars employing high angles of fireare generally quite old to the art. At one time large caliber weapons of12 inch diameter with shells weighing over 1,000 pounds were used forseacoast defenses with a view to penetrating the decks of warships. Thecontinued and most common use of this type of weapon is as a small handserviced weapon employed by infantry troops. It is a common practice totire the weapon at an angle of elevation above 45. The range isincreased by depressing the angle of fire. Improvisations to increasethe range under the press of battle condition has been accomplished byattaching additional propellant charges to the mortar shell prior todropping the shell into the barrel. Weapons of this category arenormally serviced or fired by dropping the projectile into the muzzle ofthe barrel. As the projectile strikes the breech of the barrel, thepropelling charge is ignited and the weapon fired. The projectiles arenormally fin stabilized and smooth bore barrels are generally used.

SUMMARY OF THE INVENTION The device of this invention employs a riflebarrel designed to spin stabilize the projectile when fired. Thepreferred embodiment employs electro-magnetic coils in the vicinity ofthe breech of the weapon which, in addition to performing function ofmomentarily retaining the projectile in the breech, as the burning ofthe propelling charge progresses, the magnets also assist in thesecondary function of expanding the malleable rotating band employed onthe projectile to facilitate the rotating band engaging the lands andgrooves of the barrel to accomplish stabilization of the weaponsprojectile. Although the later detailed description will describemechanical retention means employing retaining pins the preferredembodiment employs an electromagnetic retaining coil located in thebreech of the weapon which operates in conjunction with appropriatecoils, a direct current force, switches and circuitry to activate theretention coil as the projectile slides down the barrel and deactivatesthe system as the weapon is fired and the projectile moves out of thebarrel. The primary object of this invention is to provide a weapon ofincreased range. This is accomplished by momentarily retaining theprojectile in the breech of the weapon to accelerate burning of thepropelling charge and increase pressures as the projectile is propelledfrom the barrel. The malleable expanding rotating band provided on theprojectile of this invention engages the lands and grooves and spinstabilizes the projectile.

Other objects, advantages, and modifications of the concept of thecombination of this invention will be apparent to those skilled in theart from a study of attached views and the following detaileddescription.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectionalized, partiallyfragmented illustration of the breech area of the barrel illustratingprincipally the electro-magnetic retention coils and the associatedbreech or firing chamber construction.

FIG. 2 is a schematic wiring diagram illustrating the DC power soruceand the associated circuitry, coils, and signal lights of the preferredembodiment.

FIG. 3 is a fragmented, sectional view of the barrel illustrating someof the detail of the construction of the on-off switch mounted in thebarrel to activate and deactivate the circuitry.

FIG. 4 is a sectionalized view of the projectile illustrating some ofthe detail of the construction of such components as the propellingcharge, orifices, rotating band, fuse, and bursting charge.

FIG. 5 is a view of the muzzle of the mortar illustrating the lands andgrooves.

FIG. 6 is a schematic illustration of a suggested alternative embodimentemploying retaining pins in combination with a hydraulic, pressuresensor control means.

FIG. 7 is a schematic illustration of mechanical retaining pins incombination with the pressure sensor and a mechanical linkage forreleasing the pins.

FIG. 8 is a schematic illustration of mechanical retaining pins inconjunction with a pressure sensor and electro-magnetic control meansfor withdrawing the pins.

FIG. 9 is a sectional view of FIG. 8 taken substantially on line 9--9looking in the direction of the arrows illustrating a possiblearrangement of the retaining pins in the breech.

A DESCRIPTION OF THE PREFERRED EMBODIMENT For a description of theconstruction and operation of the preferred embodiment, reference ismade to the attached views wherein identical reference characters willbe utilized to refer to identical or equivalent components throughoutthe several views and the following detailed description of thepreferred embodiment.

In constructing the preferred embodiment, the conventional base plate,support arms, and sighting means well known to the art will be employed.Accordingly, they will not be described in detail.

The mortar barrel 10 is of tubular construction and may employ hot orcold extrusion or centrifugal casting techniques. The tube 11 isconstructed with lands 12 and grooves 13. The firing chamber of theweapon will be referred to as the breech l4, and the point of exit asthe muzzle 15. Some of the principal non-conventional components of thisinvention pertaining to those elements illustrated in FIG. 1 in thebreech 14 area of the mortar barrel 10. The magnetic core 17 should beconstructed from high permeability iron and might well be of slightlylarger diameter than the interior diameter of tube 11 placed andretained in position by heating tube 11 and shrinking it on to themagnetic core 17. This magnetic core 17 comprises an outer wall 18, acore base 19, and the center core 20. Tail guide 21 is preferablyconstructed of paramagnetic stainless steel. The selection of thismaterial is prompted by durability as well as improved function of thepreferred embodiment. This tail guide 21 may be threadably secured tocenter core 20. Secured to or integral with the center core is firingpin 22. The construction of the device might well include a bottom cover23 threadably encasing the tube 11 and magnetic core 17.

Mounted internally of magnetic core 17 and tail guide 21 is firstretention coil 25. This coil 25 encircles center core 20 and is employedsingly for short range firing. The first retention coil 25 is employedin conjunction with second retention coil 26 which is wound around andencases tail guide 21 to accomplish maximum retention and maximum range.Mounted in the mortar tube 11 at some point above breech 14 is theon-off switch 27 substantially in the configuration illustrated in FIG.3. Integral with or secured to mortar barrel 10 are mounted the variouselectrical components illustrated in FIG. 2. To activate the first 25and/or second 26 retention coils an appropriate DC source of power 28such as a battery is employed. The circuitry is preferably protected bycircuit fuse 29 or an equivalent structure such as a circuit breaker. Toadjust strength of the retention force in the first 25 and/or second 26retention coils an adjustable potentiometer 30 is suggested. A levertype first switch 31 activates the circuit. The first switch 31completes the circuitry to short-range coil 25 and short-range signallight 32. The second switch 33 activates the second or long-rangeretention coil 26 as well as second coil signal light 34. Onoff switch27 illustrated in FIG. 3 is placed in an operable position foractivation by projectile 37 as it moves in and out of mortar tube 11.

For a detailed description of the construction of the projectile 37 ofthe preferred embodiment, reference is made to FIG. 4. The projectile 37is constructed in the general configuration illustrated and comprises abody portion 38 and a tail portion 39. The two main portions of theprojectile are constructed in the conventional manner and may bethreadably secured together. Positioned between the body portion 38 andthe tail portion 39 is a malleable rotating band 40. This band 40 isconstructed of a soft metal such as copper and includes a round or ovalexpansion core 41 which comprises a hollow space internal of therotating band 40. The propulsion of the projectile 37 is accomplished bythe propellant body 42 which is threadably secured adjacent to the bodyportion 38. This portion of the projectile 37 is constructed in aconfiguration compatible with the contour of magnetic core 17particularly compatible with the outer wall 18 and tail guide 21. Theconstruction of propellant body 42 should utilize heat resistant metalsuch as iron or steel and be constructed with six thrust orifices 43equally spaced around its lower perimeter. Secured to propellant body 42is the projectiles cylindrical tail 44 which is constructed of metal ofhigh permeability such as iron. In the center of the cylindrical tail 44is machined a space for the propulsion detonator 45 components. At thelower extremity of cylindrical tail 44 is detonation primer 46. Theprimer 46 is interconnected to the propelling charge 48 ofnitrocellulose or cordite powder. Secured to forward portion ofprojectile 37 is point fuse 49. This device is preferably threadablysecured in order that it may be detached and readily attached to avoidthe hazards of transporting fused projectiles 37. Various methods ofattaching the components are possible; however, fuse threads 50,propulsion body threads 51, and cylindrical tail threads 52 aresuggested in the preferred embodiment. The projectile body 38 wouldnormally encase a bursting charge 53 which might be TNT, Explosive D, orphosphorous. The type is selected in accordance with the mission.

Though not considered to be the preferred embodiment, various selectedmethods of employing mechanical means to utilize the broadest concept ofthis invention are illustrated in FIGS. 6, 7, 8, and 9. These conceptseach employ retaining pins 56 which are constructed in the breech 14portion of mortar barrel 10. Equal spacing of these pins 56 aresuggested in FIG. 9. The manner in which they may contact or engage theprojectile 37 and various operable means for withdrawing the pins 56 areillustrated in FIGS. 6, 7, and 8. All the device must employ propulsionpressure sensors 57 which communicate with breech area 14 of the weapon.For a schematic illustration of hydraulic embodiment, your attentionisparticularly invited to FIG. 6. Operably secured to the propulsionpressure sensor 57 is a hydraulic sender 58 which communicates with ahydraulic conduit 59 operably engaging hydraulic receiver 60 whichactivates pin withdrawing linkage 61. Lever 62 acting over fulcrum 63would by the interaction of drive arm 64 and withdrawal arm 65 releaserestraining pin 56.

For a structure which is entirely mechanical, reference is made to FIG.7. Propulsion pressure sensor 57 is employed in conjuction withmechanical sender 68 in conjunction with a receiving arm 69 and a pinwithdrawal arm 70. This linkage or variations thereof could accomplishextracting of retaining pins 56.

For an illustration of a suggested construction of an electricalembodiment of this mechanical embodiment, reference is made to FIG. 8.In conjunction with propulsion pressure sensor 57 an electrical sender73 is employed. This sender 73, when activated, contacts sender contactswitch 74 in circuit with a DC power source 75 which activates pin coil76. The electromagnetic force on the pin coil core 77 through pincircuit 78 would result in a withdrawing of retaining pins 56. Theconcept endeavored to be illustrated and described in the foregoingschematics incorporates the principal of employing retaining pins 56 inthe breech of a mortar and are designed to temporarily restrain theprojectile and the pressure is increased at which time the retainingpins 56 are withdrawn thereby accomplishing an increased range for theweapon.

OPERATION As in utilization of the conventional mortar, sights areadjusted for the selected range and direction. In firing the device ofthe preferred embodiment, the first switch 31 is activated to magnetizethe first retention coil 25. If maximum retention and maximum range isdesired, the second switch 33 is placed in contact magnetizing alsosecond retention coil 26. On-off switch 27 is activated. Following thisprocedure the desired projectile 37 is dropped tail first into themuzzle 15 of tube 11. As projectile 37 moves toward breech 14, itscontacting of on-off switch 27 activates the first 25 and second 26retention coil. Cylindrical tail 44 progresses into tail guide 21 andthe magnetic force seats projectile 37 firmly against outer wall 18.Contact of the upper edge of outer wall 18 firmly against the malleablerotating band 40 through interaction of the components and expansioncore 41 expands rotating band 40 to its maximum diameter. Detonatorprimer 46 contacts firing pin 22. Ignition through propulsion detonator45 ignites propelling charge 48, as burning proa. a magnetic coremounted in the breech of said gresses gases are expelled through thethrust orifices mortar barrel,

43. The magnetic retention force of retention coils 25 b. a malleablerotating band secured to said projecand 26 momentarily retain projectile37 in the breech tile,

14 of the weapon. Burning and pressure progresses 5 c. said magneticcore and said malleable rotating until the pressures are adequate toovercome the retenband compatibly constructed and arranged to comtionforce at which time the projectile 37 moves rapidly press d expand saidmall ble rotating ba d forward in mortar barrel 10. As projectile movesout of upon fir contact with th s id magnetic core.

the tube 11, the on-off switch 27 is contacted deactivat- 5, Th i ti f li 1 f rther co rising;

ing circuit to Conserve DC Source This Operation 10 a. a first retentioncoil secured adjacent the breech results in advance burning orpropelling charge 48, inf id mortar b r l,

creased Pressures Within mortar barrel and b. a source of direct currentof adequate potential to creased range for Projectile activate andmagnetize said first retention coil, and

The p is' s 11 embodiment illustrated in c. conductor meansinterconnecting said direct cur- FIGS. 6, 7, 8, and 9 are comparable.Retaining pins 56 15 rent Source and Said first retention r can bespring loaded in Such a manner as m be forced 6. The invention of claim5 further comprising a secoutward similar to switch 27 as the projectile37 arrives and retention coil, Said conductor means adapted to atfhe F Q14 of the Weaponl 56 engage and selectively activate said first and saidsecond retention tain pro ectile 37 as detonator primer 46 is contactedcoils for a maximum retention f and ,propenmg charge 48 Retaining pms 7.A mortar and projectile system comprising: commue to engage thePYOJCCFIIE 37 pressures m a. a mortar barrel having a breech end and amuzzle the breech activate propulsion pressure sensor 57 end whichthrough either hydraulic sender 58, mechanical b a projectileconstructed and arranged to be sender 68, or electrical sender 73activate the various pened from Said mortar barrel fizs g izi ggi gi glg z f xgi lz is c. a propelling charge in association with said pro ecrling Ciifl'g 48 This retention funct ion and t he Zdilleisald charg-ebemg adapted propell-Skim mvanced burnin of to em char e 48 results inin ectile from said breech when said charge lS ignited, g g g d. meansfor igniting said propelling charge adjacent creased pressures withinmortar barrel 10 which results the breech end of said mortar inincreased range similar to the preferred embodiment aforedescribed inmore detail e. mechanicai restraining means for temporarily re- Asindicated the preferred embodiment is the elecstraining Said f as thebummg. of said protro-magnetic version of the device illustrated inFIGS. penmg charge ls ".lsututed and genrated l, 2, 3, and 4. Threealternative embodiments have press.ures of gP charge overcome Saldmebeen schematically described. Other modifications inchanical resirammgi i f. said mechanical restraining means further compriscorporate thebasic principals of this invention will appear to those skilled in thearts from a study of the forel going detailed description and thevarious views. fi i fi fg sensorbcomlmumcatmg What is desired to beclaimed is all embodiments of f Sal am i this invention not departingfrom the scope of equiva 40 2. a restraining pin secured to said mortarbarrel said [ems of the appended Claims restraining pin adapted tocontact and selectively I Claim. engage and retain said projectile, l. Amortar and projectile system comprising: 3. ahydraulic pin withdrawallinkage positioned adjaa' a mortal. barre] having a breech end and amuzzle cent said breech of said mortar being in a position and 5 toengage and release a projectile, and b. a projectile constructed andarranged to be proy f means operably interconnecting said peued fromsaid mortar ban-e1 propulsion pressure sensor and said hydraulic pin c.a propelling charge in association with said projecwithdrawal lmkagearranged to tile, said charge being adapted to propell said pro-Withdraw Sa1d re5t1' ammg P responsive to P p jectile from said barrelwhen said charge is ignited, Pressure i f d. means for igniting saidpropelling charge adjacent A mortar and PQlf System compl'lsmgi thebreech end f Said mortar barrel and a. a mortar barrel having a breechend and a muzzle e. a magnet restraining means for temporarilyrestraining the said projectile as the burning of said a Projectilecfmstructed and arranged to be p propelling charge is initiated anduntil generated Pelled Q Sald moftar f i. u pressures of propellantcombustion overcomes said a P PF Charge assoclatlon with 531d P firestraining means tile, said charge being adapted to propell said pro-2. The invention of claim 1 wherein said restraining jectile from Saidbreech when Said charge is ignited, means is an ejectrmmagnet, d. meansfor igniting said propelling charge adjacent 3. The invention of claim 1further comprising: the bfeefih 6nd of fl r. a. lands and groovesconstructed in said mortar baremechamcal restraining means fortemporarily rer straining said projectile as the burning of said prob. arotating band constructed integral with said propelling charge isinstituted and until generated jectile, said rotating band constructedand arpressures of propelling charge overcome said meranged to engagesaid lands and grooves and rotate said projectile. 4. The invention ofclaim 1 further comprising:

chanical restraining means, f. wherein said mechanical restraining meanscomprises:

and

4. conductor means operably interconnecting said propulsion pressuresensor and said electromagnetic pin withdrawal means constructed andarranged to withdraw said restraining pin responsive to the propulsionpressure in said breech.

1. A mortar and projectile system comprising: a. a mortar barrel havinga breech end and a muzzle end, b. a projectile constructed and arrangedto be propelled from said mortar barrel, c. a propelling charge inassociation with said projectile, said charge being adapted to propellsaid projectile from said barrel when said charge is ignited, d. meansfor igniting said propelling charge adjacent the breech end of saidmortar barrel, and e. a magnet restraining means for temporarilyrestraining the said projectile as the burning of said propelling chargeis initiated and until generated pressures of propellant combustionovercomes said restraining means.
 2. The invention of claim 1 whereinsaid restraining means is an electro-magnet.
 2. a restraining pinsecured to said mortar barrel, said restraining pin adapted to contactand selectively engage and retain said projectile,
 2. a restraining pinsecured to said mortar barrel, said restraining pin adapted to contactand selectively engage and retain said projectile,
 3. a hydraulic pinwithdrawal linkage positioned adjacent said breech of said mortar beingin a position to engage and release a projectile, and
 3. anelectro-magnetic pin withdrawal linkage positioned adjacent said breechof said mortar being in a position to engage and release a projectile,and
 3. The invention of claim 1 further comprising: a. lands and groovesconstructed in said mortar barrel, b. a rotating band constructedintegral with said projectile, said rotating band constructed andarranged to engage said lands and grooves and rotate said projectile. 4.The invention of claim 1 further comprising: a. a magnetic core mountedin the breech of said mortar barrel, b. a malleable rotating bandsecured to said projectile, c. said magnetic core and said malleablerotating band compatibly constructed and arranged to compress and expandsaid malleable rotating band upon firm contact with the said magneticcore.
 4. conductor means operably interconnecting said propulsionpressure sensor and said electro-magnetic pin withdrawal meansconstructed and arranged to withdraw said restraining pin responsive tothe propulsion pressure in said breech.
 4. hydraulic means operablyinterconnecting said propulsion pressure sensor and said hydraulic pinwithdrawal linkage constructed and arranged to withdraw said restrainingpin responsive to propulsion pressure in said breech.
 5. The inventionof claim 1 further comprising: a. a first retention coil securedadjacent the breech of said mortar barrel, b. a source of direct currentof adequate potential to activate and magnetize said first retentioncoil, and c. conductor means interconnecting said direct current sourceand said first retention coil.
 6. The invention of claim 5 furthercomprising a second retention coil, said conductor means adapted toselectively activate said first and said second retention coils for amaximum retention force.
 7. A mortar and projectile system comprising:a. a mortar barrel having a breech end and a muzzle end, b. a projectileconstructed and arranged to be propelled from said mortar barrel, c. apropelling charge in association with said projectile, said charge beingadapted to propell said projectile from said breech when said charge isignited, d. means for igniting said propelling charge adjacent thebreech end of said mortar, e. mechanical restraining means fortemporarily restraining said projectile as the burning of saidpropelling charge is instituted and until generated pressures ofpropelling charge oVercome said mechanical restraining means, f. saidmechanical restraining means further comprising:
 8. A mortar andprojectile system comprising: a. a mortar barrel having a breech end anda muzzle end, b. a projectile constructed and arranged to be propelledfrom said mortar barrel, c. a propelling charge in association with saidprojectile, said charge being adapted to propell said projectile fromsaid breech when said charge is ignited, d. means for igniting saidpropelling charge adjacent the breech end of sair mortar, e. mechanicalrestraining means for temporarily restraining said projectile as theburning of said propelling charge is instituted and until generatedpressures of propelling charge overcome said mechanical restrainingmeans, f. wherein said mechanical restraining means comprises: